This invention relates to a shock absorbing apparatus for suppressing the rolling of an automobile engine.
Recently, automatic transmission vehicles have become prevalent. In a vehicle of this type, torques, generated by the power device, differ in an idling or steady drive state and an automatic gear changing state of the automatic transmission. In the idling of steady drive state, a high-frequency and small-magnitude signal is generated, so that a low torque is generated from the power device. However, in the automatic gear changing state, a low-frequency and large-magnitude signal is generated, so that a high torque is generated.
In a vehicle generating different torques, shock absorbing members, as shown in FIG. 1, having a nonlinear spring characteristic are conventionally disposed between the engine and vehicle body, so as to decrease transmission of the torque (vibration) to the body frame and provide a comfortable drive. The shock absorbing member has an inner cylinder a and an outer cylinder b, as shown in FIG. 2. A rubber plate c is disposed to couple the inner cylinder a and the outer cylinder b. The inner cylinder a is fixed on the engine, and the outer cylinder b is fixed on the body frame, so that the rubber plate c absorbs the shock. However, in a large engine which generates a large torque, the vibration or shock cannot be absorbed by only the rubber plate c. When an automatic gear change occurs, shock occurs. In order to absorb such a shock, as shown in FIG. 3, liquid chambers f and g are formed by upper and lower mount rubber members d and e. An orifice h is formed between the liquid chambers f and g. A portion i is fixed on the body frame and a portion j is mounted on the engine. The shock is absorbed by utilizing a damping force generated when the liquid passes through the orifice h. When vibration having a large magnitude occurs, the damping force occurs by an action between the liquid and the orifice h. However, when a small shock or displacement occurs, the liquid does not pass through the orifice h due to the resistance of the orifice h. Therefore, a spring constant is increased, and a transfer force of the shock is increased, resulting in inconvenience.